/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.tomcat.util.modeler;

import javax.management.MBeanOperationInfo;
import javax.management.MBeanParameterInfo;
import java.util.Locale;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

/**
 * <p>Internal configuration information for an <code>Operation</code>
 * descriptor.</p>
 *
 * @author Craig R. McClanahan
 */
public class OperationInfo extends FeatureInfo {

	static final long serialVersionUID = 4418342922072614875L;

	// ----------------------------------------------------------- Constructors
	protected final ReadWriteLock parametersLock = new ReentrantReadWriteLock();


	// ----------------------------------------------------- Instance Variables
	protected String impact = "UNKNOWN";
	protected String role = "operation";
	protected ParameterInfo parameters[] = new ParameterInfo[0];
	/**
	 * Standard zero-arguments constructor.
	 */
	public OperationInfo() {
		super();
	}


	// ------------------------------------------------------------- Properties

	/**
	 * The "impact" of this operation, which should be a (case-insensitive)
	 * string value "ACTION", "ACTION_INFO", "INFO", or "UNKNOWN".
	 */
	public String getImpact() {
		return this.impact;
	}

	public void setImpact(String impact) {
		if (impact == null)
			this.impact = null;
		else
			this.impact = impact.toUpperCase(Locale.ENGLISH);
	}

	/**
	 * The role of this operation ("getter", "setter", "operation", or
	 * "constructor").
	 */
	public String getRole() {
		return this.role;
	}

	public void setRole(String role) {
		this.role = role;
	}

	/**
	 * The fully qualified Java class name of the return type for this
	 * operation.
	 */
	public String getReturnType() {
		if (type == null) {
			type = "void";
		}
		return type;
	}

	public void setReturnType(String returnType) {
		this.type = returnType;
	}

	/**
	 * The set of parameters for this operation.
	 */
	public ParameterInfo[] getSignature() {
		Lock readLock = parametersLock.readLock();
		try {
			readLock.lock();
			return this.parameters;
		} finally {
			readLock.unlock();
		}
	}

	// --------------------------------------------------------- Public Methods

	/**
	 * Add a new parameter to the set of arguments for this operation.
	 *
	 * @param parameter The new parameter descriptor
	 */
	public void addParameter(ParameterInfo parameter) {

		Lock writeLock = parametersLock.writeLock();
		try {
			writeLock.lock();
			ParameterInfo results[] = new ParameterInfo[parameters.length + 1];
			System.arraycopy(parameters, 0, results, 0, parameters.length);
			results[parameters.length] = parameter;
			parameters = results;
			this.info = null;
		} finally {
			writeLock.unlock();
		}
	}

	/**
	 * Create and return a <code>ModelMBeanOperationInfo</code> object that
	 * corresponds to the attribute described by this instance.
	 */
	MBeanOperationInfo createOperationInfo() {

		// Return our cached information (if any)
		if (info == null) {
			// Create and return a new information object
			int impact = MBeanOperationInfo.UNKNOWN;
			if ("ACTION".equals(getImpact()))
				impact = MBeanOperationInfo.ACTION;
			else if ("ACTION_INFO".equals(getImpact()))
				impact = MBeanOperationInfo.ACTION_INFO;
			else if ("INFO".equals(getImpact()))
				impact = MBeanOperationInfo.INFO;

			info = new MBeanOperationInfo(getName(), getDescription(),
					getMBeanParameterInfo(),
					getReturnType(), impact);
		}
		return (MBeanOperationInfo) info;
	}

	protected MBeanParameterInfo[] getMBeanParameterInfo() {
		ParameterInfo params[] = getSignature();
		MBeanParameterInfo parameters[] =
				new MBeanParameterInfo[params.length];
		for (int i = 0; i < params.length; i++)
			parameters[i] = params[i].createParameterInfo();
		return parameters;
	}
}
